The H2-C is good for at least up to 2.5A before stepdown when fed with 2S cells, and for sure it'll do at least a bit more but no one experimented with higher current output values. See Jensen567's Buck and Boost Drivers, Testing, Modding, and Discussion thread.
With regards to drivers with super high stock current output values, this is something which we'd need some driver manufacturer to assess. As a rule they stick to maximum specified driving currents for the target emitters, which is understandable but maybe modder insufficient with what it entails concerning component selection. 
^:)